2 * Copyright 1999-2021 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
10 /* S/MIME utility function */
16 #include <openssl/crypto.h>
17 #include <openssl/pem.h>
18 #include <openssl/err.h>
19 #include <openssl/x509_vfy.h>
20 #include <openssl/x509v3.h>
22 static int save_certs(char *signerfile, STACK_OF(X509) *signers);
23 static int smime_cb(int ok, X509_STORE_CTX *ctx);
27 #define SMIME_SIGNERS 0x40
28 #define SMIME_ENCRYPT (1 | SMIME_OP)
29 #define SMIME_DECRYPT (2 | SMIME_IP)
30 #define SMIME_SIGN (3 | SMIME_OP | SMIME_SIGNERS)
31 #define SMIME_VERIFY (4 | SMIME_IP)
32 #define SMIME_PK7OUT (5 | SMIME_IP | SMIME_OP)
33 #define SMIME_RESIGN (6 | SMIME_IP | SMIME_OP | SMIME_SIGNERS)
35 typedef enum OPTION_choice {
37 OPT_ENCRYPT, OPT_DECRYPT, OPT_SIGN, OPT_RESIGN, OPT_VERIFY,
38 OPT_PK7OUT, OPT_TEXT, OPT_NOINTERN, OPT_NOVERIFY, OPT_NOCHAIN,
39 OPT_NOCERTS, OPT_NOATTR, OPT_NODETACH, OPT_NOSMIMECAP,
40 OPT_BINARY, OPT_NOSIGS, OPT_STREAM, OPT_INDEF, OPT_NOINDEF,
41 OPT_CRLFEOL, OPT_ENGINE, OPT_PASSIN,
42 OPT_TO, OPT_FROM, OPT_SUBJECT, OPT_SIGNER, OPT_RECIP, OPT_MD,
43 OPT_CIPHER, OPT_INKEY, OPT_KEYFORM, OPT_CERTFILE, OPT_CAFILE,
44 OPT_CAPATH, OPT_CASTORE, OPT_NOCAFILE, OPT_NOCAPATH, OPT_NOCASTORE,
45 OPT_R_ENUM, OPT_PROV_ENUM, OPT_CONFIG,
47 OPT_IN, OPT_INFORM, OPT_OUT,
48 OPT_OUTFORM, OPT_CONTENT
51 const OPTIONS smime_options[] = {
52 {OPT_HELP_STR, 1, '-', "Usage: %s [options] [cert...]\n"},
54 OPT_SECTION("General"),
55 {"help", OPT_HELP, '-', "Display this summary"},
56 {"in", OPT_IN, '<', "Input file"},
57 {"inform", OPT_INFORM, 'c', "Input format SMIME (default), PEM or DER"},
58 {"out", OPT_OUT, '>', "Output file"},
59 {"outform", OPT_OUTFORM, 'c',
60 "Output format SMIME (default), PEM or DER"},
61 {"inkey", OPT_INKEY, 's',
62 "Input private key (if not signer or recipient)"},
63 {"keyform", OPT_KEYFORM, 'f', "Input private key format (ENGINE, other values ignored)"},
64 #ifndef OPENSSL_NO_ENGINE
65 {"engine", OPT_ENGINE, 's', "Use engine, possibly a hardware device"},
67 {"stream", OPT_STREAM, '-', "Enable CMS streaming" },
68 {"indef", OPT_INDEF, '-', "Same as -stream" },
69 {"noindef", OPT_NOINDEF, '-', "Disable CMS streaming"},
72 OPT_SECTION("Action"),
73 {"encrypt", OPT_ENCRYPT, '-', "Encrypt message"},
74 {"decrypt", OPT_DECRYPT, '-', "Decrypt encrypted message"},
75 {"sign", OPT_SIGN, '-', "Sign message"},
76 {"resign", OPT_RESIGN, '-', "Resign a signed message"},
77 {"verify", OPT_VERIFY, '-', "Verify signed message"},
79 OPT_SECTION("Signing/Encryption"),
80 {"passin", OPT_PASSIN, 's', "Input file pass phrase source"},
81 {"md", OPT_MD, 's', "Digest algorithm to use when signing or resigning"},
82 {"", OPT_CIPHER, '-', "Any supported cipher"},
83 {"pk7out", OPT_PK7OUT, '-', "Output PKCS#7 structure"},
84 {"nointern", OPT_NOINTERN, '-',
85 "Don't search certificates in message for signer"},
86 {"nodetach", OPT_NODETACH, '-', "Use opaque signing"},
87 {"noattr", OPT_NOATTR, '-', "Don't include any signed attributes"},
88 {"binary", OPT_BINARY, '-', "Don't translate message to text"},
89 {"signer", OPT_SIGNER, 's', "Signer certificate file"},
90 {"content", OPT_CONTENT, '<',
91 "Supply or override content for detached signature"},
92 {"nocerts", OPT_NOCERTS, '-',
93 "Don't include signers certificate when signing"},
95 OPT_SECTION("Verification/Decryption"),
96 {"nosigs", OPT_NOSIGS, '-', "Don't verify message signature"},
97 {"noverify", OPT_NOVERIFY, '-', "Don't verify signers certificate"},
99 {"certfile", OPT_CERTFILE, '<', "Other certificates file"},
100 {"recip", OPT_RECIP, '<', "Recipient certificate file for decryption"},
102 OPT_SECTION("Email"),
103 {"to", OPT_TO, 's', "To address"},
104 {"from", OPT_FROM, 's', "From address"},
105 {"subject", OPT_SUBJECT, 's', "Subject"},
106 {"text", OPT_TEXT, '-', "Include or delete text MIME headers"},
107 {"nosmimecap", OPT_NOSMIMECAP, '-', "Omit the SMIMECapabilities attribute"},
109 OPT_SECTION("Certificate chain"),
110 {"CApath", OPT_CAPATH, '/', "Trusted certificates directory"},
111 {"CAfile", OPT_CAFILE, '<', "Trusted certificates file"},
112 {"CAstore", OPT_CASTORE, ':', "Trusted certificates store URI"},
113 {"no-CAfile", OPT_NOCAFILE, '-',
114 "Do not load the default certificates file"},
115 {"no-CApath", OPT_NOCAPATH, '-',
116 "Do not load certificates from the default certificates directory"},
117 {"no-CAstore", OPT_NOCASTORE, '-',
118 "Do not load certificates from the default certificates store"},
119 {"nochain", OPT_NOCHAIN, '-',
120 "set PKCS7_NOCHAIN so certificates contained in the message are not used as untrusted CAs" },
121 {"crlfeol", OPT_CRLFEOL, '-', "Use CRLF as EOL termination instead of CR only"},
128 {"cert", 0, 0, "Recipient certs, used when encrypting"},
132 int smime_main(int argc, char **argv)
135 BIO *in = NULL, *out = NULL, *indata = NULL;
136 EVP_PKEY *key = NULL;
138 STACK_OF(OPENSSL_STRING) *sksigners = NULL, *skkeys = NULL;
139 STACK_OF(X509) *encerts = NULL, *other = NULL;
140 X509 *cert = NULL, *recip = NULL, *signer = NULL;
141 X509_STORE *store = NULL;
142 X509_VERIFY_PARAM *vpm = NULL;
143 EVP_CIPHER *cipher = NULL;
144 EVP_MD *sign_md = NULL;
145 const char *CAfile = NULL, *CApath = NULL, *CAstore = NULL, *prog = NULL;
146 char *certfile = NULL, *keyfile = NULL, *contfile = NULL;
147 char *infile = NULL, *outfile = NULL, *signerfile = NULL, *recipfile = NULL;
148 char *passinarg = NULL, *passin = NULL, *to = NULL, *from = NULL;
149 char *subject = NULL, *digestname = NULL, *ciphername = NULL;
151 int noCApath = 0, noCAfile = 0, noCAstore = 0;
152 int flags = PKCS7_DETACHED, operation = 0, ret = 0, indef = 0;
153 int informat = FORMAT_SMIME, outformat = FORMAT_SMIME, keyform =
155 int vpmtouched = 0, rv = 0;
157 const char *mime_eol = "\n";
158 OSSL_LIB_CTX *libctx = app_get0_libctx();
160 if ((vpm = X509_VERIFY_PARAM_new()) == NULL)
163 prog = opt_init(argc, argv, smime_options);
164 while ((o = opt_next()) != OPT_EOF) {
169 BIO_printf(bio_err, "%s: Use -help for summary.\n", prog);
172 opt_help(smime_options);
176 if (!opt_format(opt_arg(), OPT_FMT_PDS, &informat))
183 if (!opt_format(opt_arg(), OPT_FMT_PDS, &outformat))
190 operation = SMIME_ENCRYPT;
193 operation = SMIME_DECRYPT;
196 operation = SMIME_SIGN;
199 operation = SMIME_RESIGN;
202 operation = SMIME_VERIFY;
205 operation = SMIME_PK7OUT;
211 flags |= PKCS7_NOINTERN;
214 flags |= PKCS7_NOVERIFY;
217 flags |= PKCS7_NOCHAIN;
220 flags |= PKCS7_NOCERTS;
223 flags |= PKCS7_NOATTR;
226 flags &= ~PKCS7_DETACHED;
229 flags |= PKCS7_NOSMIMECAP;
232 flags |= PKCS7_BINARY;
235 flags |= PKCS7_NOSIGS;
245 flags |= PKCS7_CRLFEOL;
253 if (!opt_provider(o))
257 conf = app_load_config_modules(opt_arg());
262 e = setup_engine(opt_arg(), 0);
265 passinarg = opt_arg();
277 /* If previous -signer argument add signer to list */
278 if (signerfile != NULL) {
279 if (sksigners == NULL
280 && (sksigners = sk_OPENSSL_STRING_new_null()) == NULL)
282 sk_OPENSSL_STRING_push(sksigners, signerfile);
284 keyfile = signerfile;
286 && (skkeys = sk_OPENSSL_STRING_new_null()) == NULL)
288 sk_OPENSSL_STRING_push(skkeys, keyfile);
291 signerfile = opt_arg();
294 recipfile = opt_arg();
297 digestname = opt_arg();
300 ciphername = opt_unknown();
303 /* If previous -inkey argument add signer to list */
304 if (keyfile != NULL) {
305 if (signerfile == NULL) {
307 "%s: Must have -signer before -inkey\n", prog);
310 if (sksigners == NULL
311 && (sksigners = sk_OPENSSL_STRING_new_null()) == NULL)
313 sk_OPENSSL_STRING_push(sksigners, signerfile);
316 && (skkeys = sk_OPENSSL_STRING_new_null()) == NULL)
318 sk_OPENSSL_STRING_push(skkeys, keyfile);
323 if (!opt_format(opt_arg(), OPT_FMT_ANY, &keyform))
327 certfile = opt_arg();
348 contfile = opt_arg();
351 if (!opt_verify(o, vpm))
358 /* Extra arguments are files with recipient keys. */
359 argc = opt_num_rest();
362 if (!app_RAND_load())
365 if (digestname != NULL) {
366 if (!opt_md(digestname, &sign_md))
369 if (ciphername != NULL) {
370 if (!opt_cipher_any(ciphername, &cipher))
373 if (!(operation & SMIME_SIGNERS) && (skkeys != NULL || sksigners != NULL)) {
374 BIO_puts(bio_err, "Multiple signers or keys not allowed\n");
379 "No operation (-encrypt|-sign|...) specified\n");
383 if (operation & SMIME_SIGNERS) {
384 /* Check to see if any final signer needs to be appended */
385 if (keyfile && !signerfile) {
386 BIO_puts(bio_err, "Illegal -inkey without -signer\n");
389 if (signerfile != NULL) {
390 if (sksigners == NULL
391 && (sksigners = sk_OPENSSL_STRING_new_null()) == NULL)
393 sk_OPENSSL_STRING_push(sksigners, signerfile);
394 if (!skkeys && (skkeys = sk_OPENSSL_STRING_new_null()) == NULL)
397 keyfile = signerfile;
398 sk_OPENSSL_STRING_push(skkeys, keyfile);
400 if (sksigners == NULL) {
401 BIO_printf(bio_err, "No signer certificate specified\n");
406 } else if (operation == SMIME_DECRYPT) {
407 if (recipfile == NULL && keyfile == NULL) {
409 "No recipient certificate or key specified\n");
412 } else if (operation == SMIME_ENCRYPT) {
414 BIO_printf(bio_err, "No recipient(s) certificate(s) specified\n");
419 if (!app_passwd(passinarg, NULL, &passin, NULL)) {
420 BIO_printf(bio_err, "Error getting password\n");
426 if (!(operation & SMIME_SIGNERS))
427 flags &= ~PKCS7_DETACHED;
429 if (!(operation & SMIME_OP)) {
430 if (flags & PKCS7_BINARY)
431 outformat = FORMAT_BINARY;
434 if (!(operation & SMIME_IP)) {
435 if (flags & PKCS7_BINARY)
436 informat = FORMAT_BINARY;
439 if (operation == SMIME_ENCRYPT) {
440 if (cipher == NULL) {
441 #ifndef OPENSSL_NO_DES
442 cipher = (EVP_CIPHER *)EVP_des_ede3_cbc();
444 BIO_printf(bio_err, "No cipher selected\n");
448 encerts = sk_X509_new_null();
451 while (*argv != NULL) {
452 cert = load_cert(*argv, FORMAT_UNDEF,
453 "recipient certificate file");
456 sk_X509_push(encerts, cert);
462 if (certfile != NULL) {
463 if (!load_certs(certfile, 0, &other, NULL, "certificates")) {
464 ERR_print_errors(bio_err);
469 if (recipfile != NULL && (operation == SMIME_DECRYPT)) {
470 if ((recip = load_cert(recipfile, FORMAT_UNDEF,
471 "recipient certificate file")) == NULL) {
472 ERR_print_errors(bio_err);
477 if (operation == SMIME_DECRYPT) {
480 } else if (operation == SMIME_SIGN) {
482 keyfile = signerfile;
487 if (keyfile != NULL) {
488 key = load_key(keyfile, keyform, 0, passin, e, "signing key");
493 in = bio_open_default(infile, 'r', informat);
497 if (operation & SMIME_IP) {
500 p7 = PKCS7_new_ex(libctx, app_get0_propq());
502 BIO_printf(bio_err, "Error allocating PKCS7 object\n");
505 if (informat == FORMAT_SMIME) {
506 p7_in = SMIME_read_PKCS7_ex(in, &indata, &p7);
507 } else if (informat == FORMAT_PEM) {
508 p7_in = PEM_read_bio_PKCS7(in, &p7, NULL, NULL);
509 } else if (informat == FORMAT_ASN1) {
510 p7_in = d2i_PKCS7_bio(in, &p7);
512 BIO_printf(bio_err, "Bad input format for PKCS#7 file\n");
517 BIO_printf(bio_err, "Error reading S/MIME message\n");
520 if (contfile != NULL) {
522 if ((indata = BIO_new_file(contfile, "rb")) == NULL) {
523 BIO_printf(bio_err, "Can't read content file %s\n", contfile);
529 out = bio_open_default(outfile, 'w', outformat);
533 if (operation == SMIME_VERIFY) {
534 if ((store = setup_verify(CAfile, noCAfile, CApath, noCApath,
535 CAstore, noCAstore)) == NULL)
537 X509_STORE_set_verify_cb(store, smime_cb);
539 X509_STORE_set1_param(store, vpm);
544 if (operation == SMIME_ENCRYPT) {
546 flags |= PKCS7_STREAM;
547 p7 = PKCS7_encrypt_ex(encerts, in, cipher, flags, libctx, app_get0_propq());
548 } else if (operation & SMIME_SIGNERS) {
551 * If detached data content we only enable streaming if S/MIME output
554 if (operation == SMIME_SIGN) {
555 if (flags & PKCS7_DETACHED) {
556 if (outformat == FORMAT_SMIME)
557 flags |= PKCS7_STREAM;
559 flags |= PKCS7_STREAM;
561 flags |= PKCS7_PARTIAL;
562 p7 = PKCS7_sign_ex(NULL, NULL, other, in, flags, libctx, app_get0_propq());
565 if (flags & PKCS7_NOCERTS) {
566 for (i = 0; i < sk_X509_num(other); i++) {
567 X509 *x = sk_X509_value(other, i);
568 PKCS7_add_certificate(p7, x);
572 flags |= PKCS7_REUSE_DIGEST;
574 for (i = 0; i < sk_OPENSSL_STRING_num(sksigners); i++) {
575 signerfile = sk_OPENSSL_STRING_value(sksigners, i);
576 keyfile = sk_OPENSSL_STRING_value(skkeys, i);
577 signer = load_cert(signerfile, FORMAT_UNDEF, "signer certificate");
580 key = load_key(keyfile, keyform, 0, passin, e, "signing key");
584 if (!PKCS7_sign_add_signer(p7, signer, key, sign_md, flags))
591 /* If not streaming or resigning finalize structure */
592 if ((operation == SMIME_SIGN) && !(flags & PKCS7_STREAM)) {
593 if (!PKCS7_final(p7, in, flags))
599 BIO_printf(bio_err, "Error creating PKCS#7 structure\n");
604 if (operation == SMIME_DECRYPT) {
605 if (!PKCS7_decrypt(p7, key, recip, out, flags)) {
606 BIO_printf(bio_err, "Error decrypting PKCS#7 structure\n");
609 } else if (operation == SMIME_VERIFY) {
610 STACK_OF(X509) *signers;
611 if (PKCS7_verify(p7, other, store, indata, out, flags))
612 BIO_printf(bio_err, "Verification successful\n");
614 BIO_printf(bio_err, "Verification failure\n");
617 signers = PKCS7_get0_signers(p7, other, flags);
618 if (!save_certs(signerfile, signers)) {
619 BIO_printf(bio_err, "Error writing signers to %s\n", signerfile);
623 sk_X509_free(signers);
624 } else if (operation == SMIME_PK7OUT) {
625 PEM_write_bio_PKCS7(out, p7);
628 BIO_printf(out, "To: %s%s", to, mime_eol);
630 BIO_printf(out, "From: %s%s", from, mime_eol);
632 BIO_printf(out, "Subject: %s%s", subject, mime_eol);
633 if (outformat == FORMAT_SMIME) {
634 if (operation == SMIME_RESIGN)
635 rv = SMIME_write_PKCS7(out, p7, indata, flags);
637 rv = SMIME_write_PKCS7(out, p7, in, flags);
638 } else if (outformat == FORMAT_PEM) {
639 rv = PEM_write_bio_PKCS7_stream(out, p7, in, flags);
640 } else if (outformat == FORMAT_ASN1) {
641 rv = i2d_PKCS7_bio_stream(out, p7, in, flags);
643 BIO_printf(bio_err, "Bad output format for PKCS#7 file\n");
647 BIO_printf(bio_err, "Error writing output\n");
655 ERR_print_errors(bio_err);
656 sk_X509_pop_free(encerts, X509_free);
657 sk_X509_pop_free(other, X509_free);
658 X509_VERIFY_PARAM_free(vpm);
659 sk_OPENSSL_STRING_free(sksigners);
660 sk_OPENSSL_STRING_free(skkeys);
661 X509_STORE_free(store);
666 EVP_MD_free(sign_md);
667 EVP_CIPHER_free(cipher);
673 OPENSSL_free(passin);
678 static int save_certs(char *signerfile, STACK_OF(X509) *signers)
683 if (signerfile == NULL)
685 tmp = BIO_new_file(signerfile, "w");
688 for (i = 0; i < sk_X509_num(signers); i++)
689 PEM_write_bio_X509(tmp, sk_X509_value(signers, i));
694 /* Minimal callback just to output policy info (if any) */
696 static int smime_cb(int ok, X509_STORE_CTX *ctx)
700 error = X509_STORE_CTX_get_error(ctx);
702 if ((error != X509_V_ERR_NO_EXPLICIT_POLICY)
703 && ((error != X509_V_OK) || (ok != 2)))